In many installations of commercial and industrial gas regulators, there is a need for automatic overpressure shut-off devices or mechanisms to protect against dangerous gas line overpressure particularly for public buildings, schools, theaters, hospitals, and similar public venues. American Meter Company is a larger supplier of gas regulators for industrial, commercial and residential applications. For example, the company makes industrial regulators such as High-Pressure Models Nos. 1800 and 2000 having an overpressure shut-off mechanism. In the event of a gas line overpressure, tripping or activating the overpressure mechanism shuts off gas flow. Thereafter, it is necessary for a maintenance person to reset the overpressure mechanism once the gas line has been restored to normal gas pressure. Additionally, when a new regulator is installed, it is common practice to test for the proper safety shut down assuring that the overpressure mechanism is in operative condition. A regulator that includes both under pressure and overpressure shut off mechanisms is shown on the website of the Elster-American Meter Company, particularly, page 5, www.elster-americanmeter.com/downloads/SB8450.pdf (last accessed Jan. 9, 2014).
The present invention is concerned solely with the overpressure shut off mechanism of the regulator. The American Meter web page literature includes two schematic diagrams showing the components of the overpressure mechanism in detail, and in the normal and tripped positions that have been reproduced as FIGS. 1 and 2 for this application. A brief explanation of the operation of the overpressure mechanism will provide background for the various functions performed by the tool of the present invention, an embodiment of which will be described below.